The Characterization of Coal Liquefaction Products Obtained under an Inert Atmosphere and Catalytic Conditions. Part II: Soluble Products

Beypazari and Tunçbilek lignite were liquefied using two different catalyst methods—physically mixing and impregnation. The liquefaction occurred under conditions of inert atmosphere and various process parameters. Solvent to coal ratio, pressure, catalyst type, catalyst concentration, temperature, and time were examined as process parameters. The most appropriate parameters for the total soluble products obtained by liquefaction of both lignites and for elemental analysis of preasphaltenes were determined as follows: 2/1 solvent to coal ratio; from 1.25 MPa to 2.50 MPa initial nitrogen pressure; Fe ₂ O ₃ and Mo(CO) ₆ as catalyst types; 3% as catalyst concentration; 400°C as reaction temperature; and 60 min as reaction time. In general, fuel quality of both preasphaltene and total soluble products decreased as temperature increased above 400°C and reaction time exceeded 60 min. The fuel quality of the preasphaltenes and the total soluble products obtained under the catalytic conditions and in the state of impregnation of catalyst onto coal is higher than under the noncatalytic conditions and in the state of physically mixing of catalyst.

Keywords:

• lignite
• catalyst
• liquefaction
• process parameters
• soluble products
• pre-asphaltenes
• characterization

Acknowledgments

The author gratefully acknowledges the support of this work (Project No: I.Ü.B.A.P.B. 2002/08) by the Scientific Research Projects Unit of Inönü University.

Notes

^a By difference, df: dry free, daf: dry ash free.